I think what you need to do is file with the sale of an investment as suggested above, and print your return and mail it instead of e-filing.
In TurboTax, go to the section for the sale of stocks and other investments. Choose "other investments", not the sale of your home. List the purchase price as $15,000 and the selling price as $15,000. Also attach a copy of the 1099 to your tax return along with a written statement explaining the circumstances. Print your return, sign it, and file by mail. Don't forget to also mail in your state return.
This transaction also reduces your basis on the remainder of your property. Whenever you sell the home and you list the sale on your tax return, reduce your original purchase price by the amount of the sale of this part of your lot, $15,000.
Both box 3 or box 7 on a 1099MISC is incorrect. It should either not be reported as income at all, or be reported on a 1099-S.
